I have a rem 7600 in 257 Roberts that I just started load developing for. Every time from a cool barrel the first shot goes 1 1/2" high and 2" left of the rest of the string. The rifle is very accurate. It will put the rest of the shots into 1/2" to 3/4" . Doesn�t matter if 3, 5 or more shots. I usually wait about 1 minute between shots. If I am shooting 10 shot groups I wait 1 minute between the first 5 then 2 minutes between the next 5. When I set the gun aside and let her cool completely it is back to the same thing.
Any one have a clue?

This is completely normal. There's your clue!

Seriously, most factory barreled rifles will throw the CCBS (cold, clean bore shot) to a different point than it puts the rest of the group.

Break Free has an evaporating solvent that I've been using to remove the oil or Hoppes number 9 from my bores prior to firing that first shot, and this seems to make at least some difference.

Most hunters will simply fire a fouling shot or two at the range or elsewhere before taking the rifle to the field.

You'll also notice that some load recipes will keep that CCBS a little closer to the main group than others will. But that 1/2 to 3/4 MOA from the load you're using would leave me to leave well enough alone!

Dan Newberry
green 788

Hold the presses!

Are you saying that the rifle will throw the first shot 2 MOA from a totally cooled barrel even if the barrel is already fouled?

That may be another matter, related to bedding, or in the case of the 7600, perhaps it is a chambering issue. It is possible that the lock-up is different for that first shot going into a cool chamber.

Are you full length sizing the brass, or neck sizing?

Dan Newberry
green 788

If your 7600 does this with ALL DIFFERENT KINDS OF AMMO you have tried, you will have to make allowance for this by zeroing the rifle for the first shot from a cold barrel, (what COL Whelen called the "sniper's zero"), and if you have to fire more than one round while hunting, you'll have to "hold off" the required amount for subsequent shots as the barrel heats up. (Unless there's some way of trying to change the "bedding" of these barrels, which I am not familiar with regarding the Rem. 740-760 series of rifles.)

This happens from a cleen cold barrel and a fould cold barrel. It happens from a full mag or empty mag.
And it accures with every load combo I have tried so far including factory loads.

This is phenomenal accuracy from a Remington pump. Most of them are pretty random about where within the 4" circle they throw their shots. Be grateful and don't look the gift horse in the mouth.

Stonecreek, that's a pretty broad brush you paint with, there. My 7600 will easily hold 1.5" for three, cold, hot or in between. FWIW, Dutch.

Dutch: As I say, be grateful and don't look a gift horse in the mouth. And in the meantime, I'll try to trim my brush down to paint a bit narrower line!

Actually, I kind of like the old Remington pumps. I have a Model 14 in .25 Remington and I think it will hold under 2" (which used to be considered good even for bolts).

I don't doubt that your 7600 will do what you say, but they are hard to do much with if they don't choose to shoot well "on their own" so to speak.

Slide action , Lever action, semi auto action rifles lack the ability to lock the cartridge tightly in the chamber, and will not equal the accuracy of a good bolt action rifle.

Since your rifle produces the same effect each time it is certain something is wrong with that particular rifle. Once the rifle bore has been fouled it should continue to place the shots in the main group. Not repeat with one shot out of the main group. You may never solve this problem but I am a perfectionist and would have that rifle taken apart and reassembled to see if it changes how it groups. A good gunsmith should be able to help you find the problem. All my rifles place all their shots in the same group or I find out why not and fix it. I would guess your lock up system or somthing is disrupting your barrel harmonics and is causing your problem. Could be a worn or misaligned or bent part in the action when you chamber that first round when the bore is stone cold.
Free floating barrels in most cases produce consistantly accurate rifles. Also a one minute waite between rounds will not give your rifle bore enough time to cool down. You should try waiting five minutes between shots. Sporter weight hunting barrels will become hot very fast and cause groups to open because of that.
Benchrest shooters must fire their groups in seven minutes and use very heavy barrels to eliminate the heat build up factor in their tiny groups.

Reloader66

Remington's 7600 uses a rotating bolt to lock the chamber. Instead of having to turn a handle on the end, you pull back on the handle and a stud working in a spiral groove in the bolt rotates the bolt to unlock it, then on reaching the end of the groove yanks the bolt backward. The 7400 semi-auto also has a rotating bolt, as does Brownings BAR (semi-auto), BPR (pump action) and BLR (lever action). How you rotate a bolt to unlock it can take many forms, all of which have equal accuracy potential as far as the chamber lockup.

I would guess that 35nut might have a barrel with just enough residual machining stresses in it that causes it to throw that first "cold" shot a little out of the group and then settle down and shoot well. If the barrel is free floating, you might try putting a shim of something between the end of the stock and the barrel to put a little upward pressure on the barrel. 2-4 thickness of a business card usually work okay, try various pressures and see if the barrel settles down. Could also try a cryo treatment of the barrel to remove any residual stresses.